Along with the rapid proliferation of wireless LANs in recent years, wireless LAN access points are being provided at railroad stations, airports, hotels, coffee shops, fast-food places, and other public places. To use such an access point, a user typically must make registration for arranging terms and conditions concerning communication charge payment and the like. Then, the user can use the access point by inputting through a terminal device an ESSID (Extended Service Set Identifier) and a WEP (Wired Equivalent Privacy) key obtained through the user registration.
A technique has been proposed in which a mobile phone is used to perform registration for using a wireless LAN access point (see Patent Document 1). According to the technique, a user first enters, through his/her mobile phone, information such as the MAC address of a communication device that will communicate with the wireless LAN access point. A gateway server, which mediates between the wireless LAN access point and a network such as the Internet, performs a registration process according to the entered information and permits access of the registered communication device to the Internet. The technique has the advantages that it is convenient because it saves the user from having to fill in and send a registration form by conventional mail and the service can be used online immediately after the registration.
The Yahoo BB! mobile service uses a technique in which when a user makes a call to a specified number from a mobile phone, an ESSID and a WEP key are issued on the basis of information such as the caller telephone number indicated to a device at the called site. The ESSID and WEP key issued are notified to the user by voice. The user enters the notified ESSID and WEP key into a communication terminal to connect to the Internet. A guideline for the security of wireless LANs will be described later (see Non-Patent Document 1).
[Patent Document 1] Published Unexamined Patent Application No. 2003-235082
[Non-Patent Document 1] Web Page URL “http://it.jeita.or.jp/perinfo/committee/pc/wirelessLAN/”